Remove the filets from the ‘fridge at least 30 minutes prior to cooking to allow them to come to room temperature. Combine the garlic powder, onion powder, paprika, and salt and pepper and season the filets on all sides.
Meanwhile, combine the crust ingredients to create a clumpy mixture (it should not be liquidy). Set aside.
Meanwhile, add the potatoes to a generously salted pot of boiling water and cook until fork-tender, then drain and place into a mixing bowl. Add half of the milk and melted butter to the potatoes and mix/mash until smooth – adding more milk and butter until the desired consistency is achieved. Add the parmesan, Extra Hot Horseradish, and salt and pepper to taste. Cover and set aside.
Preheat the oven to 400 degrees and heat a cast iron skillet over medium-high heat.
Add 2 tbsp of high-heat oil to the skillet and warm until shimmering. Sear the filets on all sides – about 2 minutes on the top and bottom and 1 minute on each side.
Top the filets with the crust and place the skillet in the oven until the crust is browned – about 5 minutes.
Allow the filets to rest before serving on top of the horseradish puree alongside your favorite veggie or greens.